Digital Commons Network^™

Evaluating How Acidic Solutions Affect The Microhardness Of Bioceramic Sealers, Colton Fischer

Theses and Dissertations

Introduction: With growing use of bioceramic sealers (BCS) in root canal therapy, there have been challenges when retreating BCS cases. Weak acids may be effective in removing BCS and their efficacy as a solvent can be measured by their influence on the microhardness of BCS. Microhardness can be used as an indirect measurement of material hardness. The purpose of this study was to investigate the microhardness of BCS when placed in contact with various acidic solutions to assess their potential use as a solvent for retreatment procedures.

Methods: EndoSequence BC Sealer (Brasseler USA) was injected into four 10 × 3mm …

Exploring The Impact Of Covid-19 On Adults With Intellectual And Developmental Disabilities In The United States, Sarah Lineberry

Theses and Dissertations

Like most disasters, the COVID-19 pandemic has disproportionately impacted people from historically marginalized communities. People with intellectual and developmental disabilities (IDD) have faced higher rates of infection, hospitalization, and death compared to people without disabilities, as well as significant disruptions to the services that support them to participate in the community. A relative lack of research about the experiences of people with IDD may have contributed to this risk and continues to limit our understanding of the impacts of COVID-19. This three-paper dissertation is guided by the theory of epistemic injustice (Fricker, 2007) to understand the impacts of COVID-19 on …

Bet Inhibition As A Strategy For Enhancing The Response To Estrogen Antagonism/Cdk4-6 Inhibition In Er Positive Breast Cancer, Ahmed M. Elshazly

Theses and Dissertations

Breast cancer is the most commonly occurring malignancy in females, accounting for the second most common cause of cancer-related deaths. ER+ breast cancer constitutes approximately 70% of all breast cancer cases. The standard care of therapy comprises endocrine antagonists together with adjuvant therapy; however, the recovery from the therapy-suppressive state is associated with further drug resistance together with increasing tumor aggressiveness and with possible metastasis. Autophagy induction has been shown to be associated with various therapeutic modalities, with different functions, including cytotoxic, cytoprotective, cytostatic as well as non-protective forms. The triggering of autophagy may be responsible for resistance development and …

Effects Of Hiv-1 Tat And Opiates On Gene Regulation Of Oligodendrocyte Lineage Cells: Identification Of Myrf As A Novel Target, Kelly M. Flounlacker

Theses and Dissertations

HIV-associated neurocognitive disorders remain pervasive even with increased efficacy/use of antiretroviral therapies. Opioid use/abuse among HIV+ individuals is documented to exacerbate deficits. White matter (WM) alterations (myelin pallor, volume/structural) detected by diffusion tensor imaging, are common observations in HIV+ individuals. Using transgenic mice expressing HIV-1 Tat, we examined effects of 2-6 weeks of Tat/morphine exposure on WM using genomic/biochemical methods. RNA sequencing of striatal tissue after 2-weeks revealed robust changes in mRNAs associated with oligodendrocyte populations/myelin integrity, including Transferrin, Ndrg1, and myelin regulatory factor (Myrf/Mrf), an oligodendrocyte-specific transcription factor involved in differentiation/maturation. Immunoblots conducted after 6-weeks exposure in …

Quantifying Insect Emergence In Tidal Freshwaters And The Importance Of Aquatic Prey In Wetland-Dependent Songbird Diet, Samantha L. Rogers

Theses and Dissertations

Insectivorous birds and their arthropod prey are experiencing widespread population declines, driven largely by anthropogenic disturbance and climate change. For wetland-dependent insectivores that consume a mixture of terrestrial and aquatic insects, understanding the availability, consumption, and nutritional qualities of aquatic diet subsidies is important for conservation. I use prothonotary warblers (Protonotaria citrea) as a model species throughout this work, because their breeding season aligns with aquatic insect emergence and they include aquatic insects when provisioning nestlings. In the first chapter, I estimate aquatic insect emergence from tidal freshwaters, which are understudied compared to nontidal systems. Using continuous field …

How Stromal Interactions Play A Role In The Quest For Human Papillomavirus Specific Cancer Therapeutics, Alexis-Leigh A. Fakunmoju

Theses and Dissertations

High-risk human papillomaviruses (HPV), like HPV16 and HPV18, are associated with malignant cancer growth within the oropharynx and cervix. Globally, HPV-induced cancers, including oropharyngeal and cervical cancers, contribute 5% to the overwhelming burden of all cancers. HPV is highly transmissible by sexual contact via micro abrasions to the mucosa. Once exposure occurs, the virus begins replication and creates an intimate relationship with the host’s cellular proteins. While most HPV is cleared quickly by our immune system, persistent infections, or infections in immune compromised individuals, are susceptible to transformation and tumor progression. Early detection measures like PAP smears and preventable measures …

Radiation Shielding Effectiveness Of Hafnium Diboride (Hfb2) Reinforced Epoxy Composites For Enhanced Radiation Protection And Safety, Furkan Erdogan

Theses and Dissertations

This thesis investigates the radiation shielding effectiveness of hafnium diboride (HfB2) reinforced epoxy composites, with the aim of enhancing radiation protection and safety in various applications. The study focuses on the development and characterization of HfB2-epoxy composites with varying weight percentages of HfB2 nanoparticles, as well as on the evaluation of their shielding effectiveness against gamma rays and thermal neutrons. The radiation shielding performance of the composites is assessed using gamma-ray spectroscopy and neutron counting, and the neutron attenuation efficacy is compared with that of 5% borated high-dense polyethylene. The results indicate that the HfB2-epoxy composites exhibit promising radiation shielding …

Structure–Activity Relationship Studies On 6-Chloro-1-Phenylbenzazepines Leads To The Identification Of A New Dopamine D1 Receptor Antagonist, Rajan Giri, Hari K. Namballa, Vishwashiv Emogaje, Wayne W. Harding

Publications and Research

The 1-phenylbenzazepine template has yielded a number of D1R-like ligands, which, though useful as pharmacological tools, have significant drawbacks in terms of selectivity versus D5R as well as pharmacokinetic behavior. A number of 1-phenylbenzazepines contain a 6-chloro functional group, but extensive SAR studies around the 6-chloro-1-phenylbenzazepine framework have not been reported in the literature. To further understand the tolerance of the 6-chloro-1-phenylbenzazepine template for various substituent groups towards affinity and selectivity at D1R, we synthesized two series of analogs with structural variations at the C-7, C-8, N-3, C-3′ and C-4′ positions. The series 2 analogs differed from …

Logic As Applied Mathematics — With Particular Application To The Notion Of Logical Form, Graham Priest

Publications and Research

The word ‘logic’ has many senses. Here we will understand it as meaning an account of what follows from what and why. With contemporary methodology, logic in this sense – though it may not always have been thought of in this way – is a branch of applied mathematics. This has various implications for how one understands a number of issues concerning validity. In this paper I will explain this perspective of logic, and explore some of its consequences with respect to the notion of logical form.

Adaptive Single Low-Light Image Enhancement By Fractional Stretching In Logarithmic Domain, Thaweesak Trongtirakul, Sos S. Agaian, Shiqian Wu

Publications and Research

Low-light image enhancement is a challenging task that aims to improve the visibility and quality of images captured in dark environments. However, existing methods often introduce undesirable artifacts such as color distortion, halo effects, blocking artifacts, and noise amplification. In this paper, we propose a novel method that overcomes these limitations by using the logarithmic domain fractional stretching approach to estimate the reflectance component of the image based on the improved Retinex theory. Moreover, we apply a simple adaptive gamma correction algorithm to the Lab color-space to adjust the brightness and saturation of the image. Our method effectively reduces the …

Predator Feeding Rates May Often Be Unsaturated Under Typical Prey Densities, Kyle E. Coblentz, Mark Novak, John Delong

School of Biological Sciences: Faculty Publications

Predator feeding rates (described by their functional response) must saturate at high prey densities. Although thousands of manipulative functional response experiments show feeding rate saturation at high densities under controlled conditions, it remains unclear how saturated feeding rates are at natural prey densities. The general degree of feeding rate saturation has important implications for the processes determining feeding rates and how they respond to changes in prey density. To address this, we linked two databases—one of functional response parameters and one on mass–abundance scaling—through prey mass to calculate a feeding rate saturation index. We find that: (1) feeding rates may …

Modelling The Relationship Between Personality Traits And Basic Emotions: A Multi-Modal And Affective Computing Approach, Brendan Ryan Donovan

Theses

In the field of Psychology, it has long been assumed that one’s personality traits are linked to one’s emotional states. Yet there is a scarce amount of research that has directly quantified the relationships between basic emotional states and Big Five personality traits. Most empirical research has investigated how attributes of emotional states map to a narrow selection of personality traits (Extraversion and Neuroticism) via a single modality (questionnaires). This narrow focus restricts the field’s understanding of the relationship between emotional states and personality traits.

In this research, the Personality Emotion Mapping (PEM) model was developed to map the relationships …

Characterisation Of Selected Microbes In Terrestrial And Simulated Extraterrestrial Habitats: Human Health And Environmental Applications, Daniel Joseph Keaney

Theses

The rapid development of the Space industry and associated technologies over the past decade is leading to the inevitable consideration of establishing human-based colonies on extra-terrestrial bodies such as the moon and Mars. With Mars being the focus of not only this body of work, but current New Space Age travel (NASA and SpaceX), a significant issue posed by Martian colonists includes establishing a safe and sustainable food source. Owing to its constantly evolving prehistoric landscape, the soils of Mars are contaminated with sodium perchlorate, a water-soluble salt that is toxic to humans, leftover from once inferred brine seeps that …

The Use Of Membrane Filtration To Increase Native Whey Protein In Infant Formula, And Effects On Bioaccessibility And Bioactivity, Yihong Chen

Theses

Breastfeeding is recognised as the gold standard for feeding newborns and infants. However, infants who cannot be breast-fed or for whom breast milk is not available, can be fed with bovine infant milk formula (IMF) as a substitute. Researchers and producers of IMF strive to continually improve or “humanise” the composition and functionality of IMF. During production of IMF it must undergo several heat treatment steps, e.g. heat-sterilisation or spray-drying, in order to provide a safe product to the infant. These heat treatments denature the globular whey proteins in IMF. In contrast, breast milk is by its nature unheated, so …

Isolation And Characterisation Of Soil-Derived Bacteria With Antimicrobial Activity Against Antibiotic Resistant Pathogens, Ellen Twomey

Theses

Bacteriocins are a diverse range of ribosomally synthesized bioactive peptides, recognised predominantly for their potent antimicrobial activity against other strains closely related to the producer. The focus of this thesis was to explore this activity and examine the potential of bacteriocins to inhibit the growth of clinically relevant pathogens. Although evidence exists in the literature to suggest that bacteriocins could be applied in a similar fashion to conventional antibiotics, to date they are only utilised as preservative in food to prevent the growth of foodborne illness causing organisms. Isolating and screening bacterial strains in order to identify bacteriocin producers has …

Leading Climate & Environmental Action In The San Diego Region, Tessa Tinkler, Eo Hanabusa, Emily Young, Darbi Berry, Connelly Meschen

Environment

Leading Climate & Environmental Action in the San Diego Region presents the state of environment-focused nonprofits in the San Diego region and their legacies that position them to continue impactful climate action. Findings in this report are synthesized from quarterly public opinion pollings (San Diego Residents Survey), surveys of 30 local environmental nonprofit leaders (Nonprofit Leaders Survey), the latest nonprofit data from the Internal Revenue Service (IRS), and data on foundation grants awarded to local nonprofits (Candid). The environmental nonprofit sector in the San Diego region is relatively small, but it has worked on the frontlines for many years to …

Techno-Economic Comparative Analysis Of Two Hybrid Renewable Energy Systems For Powering A Simulated House, Including A Hydrogen Vehicle Load At Jeju Island, Christelle Arielle Mbouteu Megaptche, Hanki Kim, Peter Moses Musau, Sebastian Waita, Bernard Aduda

All Rsif Scholars' Publications

This work undertakes a techno‑economic comparative analysis of the design of photo‑ voltaic panel/wind turbine/electrolyzer‑H2 tank–fuel cell/electrolyzer‑H2 tank (configuration 1) and photovoltaic panel/wind turbine/battery/electrolyzer‑H2 tank (configuration 2) to supply electricity to a simulated house and a hydrogen‑powered vehicle on Jeju Island. The aim is to find a system that will make optimum use of the excess energy produced by renewable energies to power the hydrogen vehicle while guaranteeing the reliability and cost‑effectiveness of the entire system. In addition to evaluating the Loss of Power Supply Probability (LPSP) and the Levelized Cost of Energy (LCOE), the search for achieving that objective …

Adoption Of Climate Smart Agricultural Technologies Among Smallholder Farmers In Semi-Arid Ghana, Mohammed Tiyumtaba Shaibu, Rose Afful, Daniel Nukpezah, Mohammed Shaibu, Darlington Sibanda

All Rsif Scholars' Publications

The evidence of climate change and variability in semi-arid Ghana is glaring and the adverse impact is being felt mostly by smallholder farmers because of their over dependence on agriculture for livelihood and subsistence. As a solution to building the resilience of the smallholder farmers, the Climate Smart Agriculture (CSA) concept was introduced a decade ago by the Food and Agriculture Organization, guided by three key principles of adaptation to climate change, greenhouse gas emissions reduction and promotion of food security. The paper sought to assess the level of awareness of climate smart agriculture practices and the respective rate of …

An Investigation Into The Irish Bread Market With A Particular Focus On Sourdough Bread. Are Increased Numbers Of Consumers Purchasing Sourdough Bread? If So, Why And What Do They Know About It?, Aisling Kelly

Theses

Bread has a long-standing history in the Irish diet and remains a staple part of our calorie intake with an average consumption of 37.5 kg per person per annum (Jocelyn, 2020; Murtagh, 2009). While the traditional breads of oatcakes and soda bread have remained a favourite for many decades, Ireland’s bread market has also evolved to include baked items from all over the world. Most recently, consumers have altered their purchasing habits in relation to bread due to the enforced restrictions on the movement of people (and consequently goods) during the COVID-19 pandemic of 2020 to 2022. Evidence suggests that …

Spatial And Temporal Varitations In Dissolved Calcium In The Kentucky Lake Watershed In Relation To Zebra Mussel Colonization, Kelsie Meystedt

Murray State Theses and Dissertations

Calcium is the fifth most abundant element on earth’s crust. Plants and animals require calcium for structure and intracellular metabolism. Recent studies have shown that dissolved calcium (Ca2+) freshwater ecosystems is of growing concern as the increasing concentrations of this element are implicated in altering the natural environment and biota. Elevated levels of dissolved calcium and sporadic re-emergence of an invasive species, namely zebra mussels (Dreissena polymorpha) in Kentucky Lake in the recent years served as a motivation for this study. The objective of this study was to determine spatial and temporal variations in dissolved calcium in selected streams, Kentucky …

Evaluating Gizzard Shad Dorosoma Cepedianum And Threadfin Shad D. Petenense Populations In Two Kentucky Reservoirs Recently Invaded With Silver Carp Hypophthalmichthys Molitrix, Nathan Klein

Murray State Theses and Dissertations

Gizzard Shad Dorosoma cepedianum and Threadfin Shad D. petenense are ecologically important fish species found in many reservoirs throughout the southeastern United States, such as Kentucky Lake and Lake Barkley. One current challenge that Gizzard Shad and Threadfin Shad may face in these two reservoirs is competition with the invasive Silver Carp Hypophthalmichthys molitrix. However, quantifying the effects of this competition may be difficult because of limited baseline population data for Gizzard Shad and Threadfin Shad in these two reservoirs. Gizzard Shad and Threadfin Shad were collected by boat electrofishing and surface trawling in cove and main channel locations …

Comparison Of Corticosterone Concentrations Between Serum And Fecal Samples As A Measure Of Stress In Male Broilers., Kayla Weinacht

Murray State Theses and Dissertations

Stress has long been a topic of interest in the poultry industry due to its potential negative effects on chicken health and production of both eggs and meat. With increased global growth in egg and broiler production, more attention has been paid to the stressors that affect chickens in modern poultry operations, particularly environmental temperature and stocking density. Improving quantitative measurement of stress is always needed in poultry welfare research. In most studies, blood serum is measured for corticosterone, one of the biomarker hormones associated with stress in chickens. Methods of collecting blood serum are by their nature disruptive to …

“I Ask Questions!”: An Investigation On Conspiracy Theorizing, Epistemic Curiosity, And Social Vigilantism In Examining Fanatic Conspiracy Theory Support, Hillary Copeland

Murray State Theses and Dissertations

This study uncovered factors associated with increased conspiracy theory fanaticism by examining the structural components of conspiracy thinking to predict continuous support for specific conspiracy theory propositions. Participants' level of discordant knowledge in conspiracy thinking, comprised of subjective certainty and locus of perceived social opposition, was quantified to predict continuous support for specific conspiracy theory propositions (H1). Findings suggest that underlying differences in the epistemic structure of conspiracy theorizing can be measured to predict the potential negative outcomes of increased conspiracy thinking. Social vigilantism was also examined as a partial mediator to help explain the relationship between discordant knowing conspiracy …

Binge Drinking In College: A Phenomenological Study, Kristin Andrews

Murray State Theses and Dissertations

This phenomenological research study examined the personal experiences, habits, and perceptions of post-secondary students who binge drink. This study was guided by 3 research questions as well as pre-existing research into collegiate binge drinking. The experiences shared by participants showed that despite serious negative outcomes, students binge drink because they feel negatives are far outweighed by the positive social interactions and fun drinking creates. While all of the participants in this study are considered binge drinkers who abuse alcohol, none of the participants considered their drinking to be problematic. The participants shared their intent to stop their current drinking patters …

Doctoral Students’ Experiences Of The Pandemic And Their Perceptions Of Grit, Josie Bryant

Murray State Theses and Dissertations

The pandemic has significantly changed societal structures and individuals’ lives. The early tragedies and stress of the pandemic affected health, relationships, families, education, work, travel, and immigration. Students who entered doctoral programs in 2020 chose a unique time to pursue an already arduous goal amidst unprecedented challenges. Using a phenomenological approach, this study explored doctoral students’ experiences during the pandemic and sought to understand their perspectives of grit. The study aimed to offer first-hand insight into the pandemic’s effects on doctoral students, and add critical contributions to understanding the necessary actions, support systems, and policies for a life in a …

An Analysis Of P-20 Education At San Ildefonso Pueblo In Northern New Mexico, United States, Martin Edward Strones

Murray State Theses and Dissertations

This research study provides an inquiry by conducting a qualitative analysis of the conditions and issues associated with students at the San Ildefonso Pueblo in Northern New Mexico. For decades the education of San Ildefonso and Native Americans who live in the State of New Mexico has been ignored. This has been just the way it was, that is, until Wilhelmina Yazzie, a Native American, saw her son struggling in an unsatisfactory school system and decided to take action. This case was originally filed in McKinley Country, New Mexico, in 2014, home to largely Native American students for the Navajo …

A Geospatial Analysis Of Crime Hotspots, Campus Safety Measures, And The Campus Community’S Perceived Safety At Murray State University, Rachel Stuckey

Murray State Theses and Dissertations

Murray State University (Murray State) is in far Western Kentucky. Murray State prides itself on being a safe campus for prospective students. In this study spatial analysis was used to analyze the relationship among crime hotspots, campus safety measures, and students’ perception of safety on campus the campus of Murray State. A survey was distributed to students to determine the areas of the campus where students feel safe and unsafe. Geographical Information Systems (GIS) were used to determine the location of crime hotspots over eight years (2014-2022) to measure the spatial relationship between logged crime hotspots and perceived safe and …

Pov - You Have Adhd: Examining Predictors Of Self-Diagnosis Of Adhd On Tiktok, Olivia Bowden

Murray State Theses and Dissertations

Online self-diagnosis refers to an individual using the internet and applying their own knowledge to diagnose themself with a disorder without the input of a professional (Farnood, 2021). Social media platforms, such as TikTok, have created an environment full of mental health related information that may not always be correct. Individuals on this app may believe the videos they watch and which may ultimately lead to self-diagnosis. There has been a trend of popular mental health disorders on appearing TikTok, such as ADHD. The present study sought to examine potential predictors of self-diagnosis of ADHD through TikTok. This study examined …

Silver Carp Hypophthalmichthys Molitrix Movements In The Lower Cumberland River And Lower Tennessee River, Miranda Belanger

Murray State Theses and Dissertations

The introduction of exotic fishes in freshwater environments has caused significant ecological and economic changes. Silver Carp Hypophthalmichthys molitrix are an invasive species in the United States but are native to large rivers in eastern Asia. This species is expanding its range throughout the Mississippi River basin, beginning with the Cumberland River and Tennessee River drainages. Although Silver Carp movement patterns have been studied in other portions of the Cumberland River and Tennessee River, the lowermost portion of both rivers below Lake Barkley Dam and Kentucky Lake Dam is a unique environment in which the movement of Silver Carp has …

Georgia End Of Pathway Assessments, Lindsey Garner

Murray State Theses and Dissertations

Georgia End of Pathway Assessments (EOPAs) are given to students by every Career, Technical, and Agriculture Education (CTAE) teacher across the state yearly. CTAE programs are awarded federal funding based on the results of the EOPAs. EOPA’s are designed to provide students with an assessment after they complete a CTAE pathway and provide the student with an industry certification. This qualitative study was designed to determine if the current EOPA’s for Georgia Agriculture Education pathways are in alignment with the current state standards for those courses. Six high school agriculture teachers from across the state of Georgia participated in this …